Improvement in rotary engines



A. C. GALLAHUEE.

RdtaFy-Engihes.

PatentedvDec.-22,1874.

UNITED YSTATES PATENT FFroE.

ALPHEUS C. GALLAHUE, OF NEW YORK, N. Y.

IMPROVEMENT IN ROTARY ENGINES.

Specification forming part of Letters Patent No.158,058, dated December 22, 1874; application filed October 24, 1874.

To all whom it may concern:

Be it known that I, ALPHnUs G. GALLAHUE, of the city of New York and State of New York, have invented certain new and useful Improvements in Rotary Engines; and I do hereby declare that the following is afull, clear, and exact description thereof, reference being had to the accompanying drawin gformin g part of this specification, and in which- Figure l represents a side elevation of a rotary engine constructed in accordance with my invention, the one side plate or cover of the working chamber being removed. Fig. 2 is a horizontal section of said engine, taken mainly through the centers of the pistons. Figs. 3 and 4 are vertical sections on the lines a no and y y, respectively, of the steam and valve chest portion of the engine.

This invention relates to that class of rotary steam-engines, applicable also as water motors or meters, in which duplicate revolving pistons mounted on shafts carrying gear-wheels outside the working chambers, said pistons being arranged to work side by side within an oblong chamber having rounded ends, are used, said pistons being composed of cylindrical bodies with cavities in and projections on or from their peripheries, to secure a close working of the pistons with each other and with the curved ends of the chamber in which they revolve.

The invention consistsin acombination, with the cavities or recesses in the peripheries of the bodies of the pistons, of intermediately-arranged radial slides controlled by springs at their backs, and preferably guided by adjustable screw-stops near their ends, the sameforming the peripherical projections or acting piston-surfaces, and, by their elastic adjustment in or out, not only having a free but close action at all times against the curved ends of the workin g chamber, but having a close and yielding fit within the cavities of the adjacent piston as the two pistons revolve in reverse directions, and whereby the bodies of the pistons may work in close contact, and the loss by leakage between them, as either slide of the one piston sweeps or travels within a cavity or recess of the other piston, is reduced. The invention also consists in a combination of packing-plates or followers, having their inner edges beveled to force out the packing, said plates or followers being located within the working chamber on its one side, the same being so constructed and arranged that they not only form yielding end or face packings to the pistons, but also extend over and cover the ends of the reversely-revolving cylinders and the ends of the pistons, whereby leakage is prevented, and the pistons and reversely-revolvin g cylinders are relieved from binding by their greater expansion than the working` chamber.

A is the working chamber, or, as it might be termed, cylinder of the engine, closed by side plates or covers B B', and being of an oblong shape, with rounded or half-round ends. The duplicate pistons are composed, in part, of cylindrical bodies G C, fast on parallel shafts D D, which are concentricwith the curved ends or working surfaces of the chamber, and wh ich, passingthroughstuffing-boxes on theonecover, B', are connected by gearing E E, to revolve in common and reverso directions, as indicated by arrows in Fig. l, and to transmit power as required. These cylindrical bodies C C meet at their peripheries and work by their radial projections in contact with the curved ends of the chamber A, also within the cavities or recesses b of the pistons, respectively, as said projections make their inner sweep or travel; but these radial project-ions are not rigidly secured to the bodies C C, but are formed of radial slides G G, forced outward and made capable of yielding by means of springs d d at their backs. By thus combining radiallyyielding slides with the intermediately arranged cavities in the two pistons, said cavities b may be of a reduced width, the slides Gr working radially in and out as they enter or leave and travel within the cavities, as shown by full and dotted lines on the meeting sides of the pistons in Fig. l, and the slides will be kept in free but close contact with the surfaces formed by the cavities till wholly clear of the latter. In this way, or by these means, the loss which usually occurs by leakage and waste between the meeting sides of the pistons in engines of this class is reduced or avoided, besides a close but free t at all times as against wear insured for the pistons with the rounded ends of the working chamber.

The springs d may have their tension adjusted by screws e, and the slides G are set outward, as occasion may require, and guided and checked from being thrown out too far, by adjustable screw-stops ff, arranged at the ends of the slides and tted to the bodies C of the pistons, so as to have a radial action within fixed limits.

The engine is propelled in either direction, as required, by introducing the steam to and exhausting it from the chamber A at opposite points of the two pistons. To this end the one cover, B, of the working chamber carries on its outside a steam-chest, H, having passages g h, the one of which is connected with the upper portion of the chamber A by a port, ,and the other passage, h, by a port, 7c, with the lower portion of said chamber. These passages g and h are put in communication, respectively, either with an inlet-pipe, I, or exhaust-pipe J, accordin g to the required direction in motion of the engine, by means of cut-away cocks or valves K K, which control, in a reversible manner, the passages g 7L relatively to the inlet and outlet pipes. The other side of the chamber A, neXt to the cover B', is fitted with packing-plates or followers L M, arranged between said cover and the ends of the pistons adjacent thereto. These plates L M, which eX- tend the full length and depth of the chamber, are constructed at their edges to form a packing-groove for a hemp or other fibrous packing, m, and are kept at some little distance apart from one another, but bot-h having a close though free fit within the chamber. The inner one, M, of these plates forms a false side for the one end of the body of each piston and for the edges of the radial slides on the same side of the working chamber to bear against, while the other ends of the bodies of the pistons and opposite edges of the radial slides bear against the cover B. The other plate, L, is made adjustable inward by means of setscrews R passing through the cover B', to provide for forcing up the plate M, through the intervention of the packing m, against the pistons, and, at the same time, forcing out the packing from the groove formed at the edges of the plates L M against the walls of the chamber A. By these means not only is the engine effectually packed against leakage, but the follower M is free to yield to any excessive expansion of the pistons over that of the chamber A, thereby avoiding binding of the pistons.

I claiml. The cylindrical bodies C C, constructed with a series of cavities, b, and mounted on shafts carrying gear-wheels on the outside of the working chamber, in combination with the radial slides G G and their springs d, constructed and arranged to operate substantially as described.

2. The combination of the adjustable sliding screw-stops ff with the springs d, the radial slides G G, the bodies C C of the pistons, and the working chamber A, essentially as described.

3. The packing-plates or followers L M, beveled on their inner edges for forcing out the packing m, and made to extend over and cover the ends of the reversely-revolving cylinders and the ends of the pistons G, in combination with the set-screw R and the working chamber, substantially as and for the purpose specied.

ALPHEUS G. GALLAHUE.

Witnesses:

MICHAEL RYAN, BENJAMIN W. HOFFMAN. 

